TY - GEN
T1 - Ultrafast photoconductivity in organic semiconductors
AU - Ostroverkhova, Oksana
AU - Cooke, David G.
AU - Hegmann, Frank A.
AU - Anthony, John E.
AU - Podzorov, Vitaly
AU - Gershenson, Michael E.
AU - Jurchescu, Oana D.
AU - Palstra, Thomas T.M.
PY - 2006
Y1 - 2006
N2 - We present comprehensive study of ultrafast charge carrier dynamics in a variety of organic molecular crystals. In all samples, we observed sub-picosecond charge photogeneration and band-like transport, characterized by (i) an increase in charge carrier mobility as the temperature decreases in a wide temperature range of at least 20 K- 300 K and (ii) mobility anisotropy in the a-b plane of the crystals. The temperature dependence of the decay dynamics of the transient photoconductivity reveals the presence of shallow trapping sites in herring-bone-type-structured crystals (such as pentacene (Pc), tetracene (Tc), and rubrene (Rub)), while such traps are apparently absent in "brick-wall"-π-stacked crystals (such as functionalized pentacene (FPc)). We also report on the measurements of the charge carrier mobility anisotropy in the a-b plane of two types of FPc single crystals. Anisotropies of approximately 3.5 and 11.6 were obtained in the crystals characterized by crystal structures favoring two-dimensional and one-dimensional charge transport, respectively, consistent with the degree of π-overlap along different directions in the crystals.
AB - We present comprehensive study of ultrafast charge carrier dynamics in a variety of organic molecular crystals. In all samples, we observed sub-picosecond charge photogeneration and band-like transport, characterized by (i) an increase in charge carrier mobility as the temperature decreases in a wide temperature range of at least 20 K- 300 K and (ii) mobility anisotropy in the a-b plane of the crystals. The temperature dependence of the decay dynamics of the transient photoconductivity reveals the presence of shallow trapping sites in herring-bone-type-structured crystals (such as pentacene (Pc), tetracene (Tc), and rubrene (Rub)), while such traps are apparently absent in "brick-wall"-π-stacked crystals (such as functionalized pentacene (FPc)). We also report on the measurements of the charge carrier mobility anisotropy in the a-b plane of two types of FPc single crystals. Anisotropies of approximately 3.5 and 11.6 were obtained in the crystals characterized by crystal structures favoring two-dimensional and one-dimensional charge transport, respectively, consistent with the degree of π-overlap along different directions in the crystals.
UR - https://www.scopus.com/pages/publications/33947628816
UR - https://www.scopus.com/pages/publications/33947628816#tab=citedBy
U2 - 10.1557/proc-0935-k03-07
DO - 10.1557/proc-0935-k03-07
M3 - Conference contribution
AN - SCOPUS:33947628816
SN - 1558998926
SN - 9781558998926
T3 - Materials Research Society Symposium Proceedings
SP - 14
EP - 19
BT - Materials Research for THz Applications
T2 - 2006 MRS Spring Meeting
Y2 - 17 April 2006 through 21 April 2006
ER -